Step 2: SSH into your device (you must be on a local WiFi network). I use Coda in my tutorial, but there are tons of other SSH tools available on the Mac. Tools like Putty work well on Windows. SSH username = "root" SSH password = "alpine".

Step 4: Your device will respring, and Cydia should now appear on your Home screen. Open Cydia, and it will begin Preparing Filesystem. It will then respring.

Step 5: Now you can use Cydia and start installing apps and tweaks via Cydia. Beware that most apps and tweaks have not been updated with iOS 6 in mind, so your mileage may vary as far as compatibility is concerned. Proceed at your own risk.